A display panel included in a display device is driven at a predetermined frame frequency. In a typical display device, the display panel is driven at a frame frequency of 60 Hz. Power consumption of the display device increases, as a number of times of driving the display panel increases. Therefore, as a method for reducing the power consumption of the display device, there is known a method of suspending drive of the display panel when a same image is displayed continuously. This method is called a suspend drive, a low-frequency drive, an intermittent drive, or the like.
Furthermore, a technique of forming a thin film transistor (hereinafter referred to as TFT) included in a pixel circuit of the display device using an oxide semiconductor has been put to practical use. For example, indium gallium zinc oxide (InGaZnO) including indium (In), gallium (Ga), zinc (Zn), or the like is used as the oxide semiconductor. The TFT using the oxide semiconductor has a feature that a leakage current when the TFT is in an off state is small. Therefore, by performing the suspend drive in the display device having the pixel circuit including the TFT using the oxide semiconductor, the number of times of driving the display panel can be reduced greatly and the power consumption of the display device can be reduced greatly, while maintaining a display quality.
A display device performing the suspend drive is described in Patent Document 1, for example. Furthermore, related to the present invention, Patent Document 2 discloses a display device which repeats a processing for selecting, as a next row, a row having a smallest total amount of potential variation from a reference row and using the selected row as a next reference row, in order to reduce power consumption.